This invention relates generally to accessories for toy or model railroad layouts and more particularly to a crossing gate for a model railroad layout that simulates a crossing gate for a full-size railroad.
Grade level crossings of railroad lines in both full-size and model railroad layouts are normally controlled by signals and/or crossing gates that warn motorists of the approach of a train and prevent all but the truly reckless from entering the grade level crossing ahead of a train which can lead to serious accidents.
Crossing gates on a full-size railroads are controlled by a complex control system that causes the gates to be lowered to prevent access to the crossing shortly before a train arrives and to be raised to allow access to resume after the train has departed. Crossing gates for model railroads typically have somewhat simpler control systems but nevertheless require the detection of approaching trains or the manual actuation of the crossing gates by an operator to simulate the operation of full-size crossing gates.
Herefore, a number of techniques has been used to detect the presence of a train. Quite commonly, an isolated rail section is provided that is shunted electrically by the passage of a train thereover thereby allowing the presence of a train to be detected. More recently, magnetic or light actuated proximity sensors have been employed to detect the passage of trains. These detectors provide some advantages over isolated rail detectors in that they can be added to existing layouts without replacing rail segments. However, they must be wired to the devices they control be they crossing gates, signals, switches or the light. While the complexity of such wiring is interesting for some, it creates obstacles to the enjoyment of the model railroading experience for others and there is a continuing need for simpler devices that retain the realism of their more complex predecessors.
It is conventional for crossing gates to guard grade level crossings from each of two possible access directions. While in actual railroads the gates may be controlled independently it is desirable in model railroad layouts to provide common control to reduce cost and complexity. Herefore, train detectors separate from the crossing gates have been employed to lower the gates in advance of an approaching train. There is a need for a simpler arrangement and it is an object of this invention to address this and other needs.
When a train approaches a crossing, a signal located remotely from the crossing can lower the gates in advance of the train. However, the gates need to remain lowered until the train has passed the crossing and the advance signal can not provide this function. Therefore, there is a need for a train sensor at the gate location to keep the gate closed while the train is passing and open it after the train has left the crossing.
In previous crossing gate designs for model trains, the mechanism to raise and lower the gate or arm has required significant space and energy. This meant that the mechanism did not appear scale size or did not operate in a realistic manner. The solenoid driven crossing gates had a very fast banging action and the solenoid had to be energized for the entire time the gate was down. Other designs with larger mechanisms required that the mechanism be under the train table, which required connecting linkages to be aligned and also required under table wiring. It is an object of this invention to overcome these shortcomings.
It is another object of this invention to provide a combination crossing gate and train detector that eliminates the need for separate train detectors to operate the crossing gate.
It is another object of this invention to provide a simple but reliable mechanical construction for a crossing gate that simulates the action of a full-size crossing gates more accurately than has been possible with some of the other mechanical constructions for model railroad crossing gates known previously.
It is another object of this invention to provide a crossing gate construction that tolerates manual operation of the crossing gate and specifically, that allows the crossing gate to be manually depressed without breaking anything.
It is another object of the crossing gate of this invention to provide a pair of crossing gate assemblies that can be arranged for guarding opposing accesses to a grade level crossing and which cooperate to provide train detection between them without the need for complex signaling wiring.
Briefly stated and in accordance with presently preferred embodiment of the invention, a model railroad crossing gate includes a base, a crossing gate mounted on the base for movement between a raised position and a lowered position, a spring coupled to the crossing gate biasing the gate to the raised position, a string attached to the crossing gate and the base for pulling the gate against the spring, and a tensioner engaging the string for pulling the gate from the raised position to the lowered position.
In accordance with another aspect of the invention, the string is led through an opening in the base and the tensioner is concealed in the base.
In accordance with another aspect of the invention, a motor is mounted in the base and coupled to the tensioner.
In accordance with another aspect of the invention, the crossing gate includes a limit sensor coupled to the tensioner for determining when the gate is fully raised or fully lowered.
In accordance with another aspect of the invention, the motor is coupled to the tensioner by a reducing gear train.
In accordance with another aspect of the invention, a controller is coupled to the tensioner for controlling the position of the gate. The controller is preferably is also coupled to the limit sensor and the motor for operating the motor to move the gate from the raised position to the lowered position or vice versa and then stop the motor.
In accordance with a preferred embodiment of the invention, the tensioner comprises a rotatable cam coupled to the string for tensioning the string as the cam is rotated.
In accordance with another aspect of the invention, the controller is responsive to an input pulse or a longer signal for moving the gate between a raised position and a lowered position.
In accordance with another aspect of the invention, a controller for a model railroad crossing gate includes a first input responsive to an input pulse for producing a crossing gate activating signal having a duration longer than the duration of the input pulse for moving the crossing gate fully between its raised and lowered position, and a second input responsive to an input signal longer than a predetermined minimum for producing a crossing gate activating signal having a duration equal the duration of the input signal.
In accordance with another aspect of the invention, the controller for a model railroad crossing gate includes an output for controlling a second controller and an input for receiving signals from a remote controller.
In accordance with another aspect of the invention, the controller includes a motor controller responsive to a crossing gate activating signal for activating a motor for controlling the position of a crossing gate.
In accordance with another aspect of the invention, a controller for a model railroad crossing gate includes a flashing controller responsive to a crossing gate activating signal for producing flashing light signals.
In accordance with another aspect of the invention, the controller includes a bell sound generator responsive to a crossing gate activating signal for producing a bell sound.
In accordance with another aspect of the invention, a model railroad crossing gate construction for guarding two accesses to a simulated grade level crossing includes a first crossing gate having a light source and a second crossing gate having a light detector. A controller in the second crossing gate maintains the crossing gate in an up position in response to a continued detection of a signal from the light source and moves the crossing gate to a lowered position if the light from the light source is interrupted by the passage of a train between the light source and the light detector. The crossing gates preferably include an electrical connection between the first and second crossing gates for synchronizing the operation of the first crossing gate having the light source with the second crossing gate having the light detector. Preferably, the light source and light detector are infrared light sources and light detectors. More preferably, the light source is a pulsed light source and the light source discriminates between pulsed light from the light and a steady ambient light.